As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AN OVERNIGHT LINE CHECK THE EMERGENCY ESCAPE PATH LIGHTS IN ROWS 22 TO 26 FAILED TO ILLUMINATE. MAINTENANCE FOUND BATTERY PACK M10568 TO BE DEFECTIVE AND REPLACED IT. SYSTEM OPERATION WAS NORMAL AFTER THE BATTERY PACK WAS REPLACED.